The present invention relates to an electronic device for use with an audio-visual system comprising a plurality of devices and its repair method, for example. More particularly, the present invention relates to an electronic device and its repair method in which defects of respective devices can be detected and repaired satisfactorily by using a digital interface laid among a plurality of devices, for example.
In an audio-visual system comprising a plurality of devices, for example, it has been proposed to transmit audio and video data and various control data among the devices by using a digital interface. Specifically, in the format of the digital interface prescribed by the IEEE (The Institute of Electrical and Electronics Engineers) 1394, for example, respective devices connected by the bus are called nodes. During one frame period, isochronous transfer mode packets and asynchronous transfer mode packets can be transmitted among the nodes connected by the bus.
When data is transmitted through the interface prescribed by the IEEE 1394, stream data of a large capacity such as video data and audio data is transmitted in the isochronous transfer mode. When data is transmitted in the isochronous transfer mode, while a predetermined transmission band is being secured in advance, transmission of data is executed so that data is transmitted in the isochronous transfer mode with a real time property being secured. However, in the isochronous transfer mode, when an error occurs in the transmission, the isochronous transfer mode has no mechanism capable of protecting data from the error so that data is lost accordingly.
Data such as control data and still picture data are transmitted in the asynchronous transfer mode. In the case of the asynchronous transfer mode, data can be transmitted by transmitting asynchronous packets from a node which secures a transmission line by executing processing called an arbitration to secure a band during a period which is not available in the isochronous transfer. In this mode, a reliable transmission can be guaranteed by executing processing of acknowledge and retry. However, when the band on the bus is secured, each packet is transmitted so that transmission timing cannot be made constant.
When a plurality of audio devices and video devices are connected by the IEEE 1394 system standard bus, a controller is able to control operation of a controlled device in a remote control fashion by transmitting various kinds of control data from one device (controller) to the other device (controlled device).
When such control data are transmitted, there can be applied a transmission system of an AV/C command (AV/C Command Transaction Set) which is a control command applied to an audio-visual device (AV device), for example. Details of the IEEE 1394 system and details of the AV/C command are laid-open in the internet home page http://www. 1394TA. org.
When an audio-visual system in which a plurality of apparatus are connected by using the above digital interface is constructed in, a home, for example, there is used an arrangement shown in FIG. 2, for example. Specifically, as shown in FIG. 2, there is provided a bus line 9 which is prescribed by the IEEE 1394, for example. To this bus line 9, there are connected a video recording and playbacking apparatus (VCR) 100 manufactured by a vender A, a disc recording and playbacking apparatus (MD) 200 manufactured by a vender B, a disc playbacking apparatus (CD) 300 manufactured by a vender C and a television receiver (TV) 400 manufactured by a vender D.
However, when the audio-visual system is constructed by using such bus line 9, if one apparatus malfunctions, an influence of the malfunctioning apparatus spreads to the whole of the bus line 9. Further, in that case, a user cannot visually specify a defective apparatus. Accordingly, in order to solve such problem, a user has to request the venders A, B, C, D to repair their own apparatus, respectively, and hence extremely a lot of time and labor should be wasted.
On the other hand, a technology capable of detecting the defective part of an apparatus and repairing the detected part by using codes which can be set to respective venders and are prescribed in the above IEEE 394 interface has been developed. However, the above technology can be implemented after the defective apparatus has been specified and therefore cannot be used when a user cannot visually specify a defective apparatus as described above.
In view of the aforesaid aspect, it is an object of the present invention to provide an electronic device and its repair method in which when a specific device in a system with a plurality of apparatus connected thereto by using a bus based on a conventional digital interface malfunctions, such defective device can be detected and repaired readily and easily.
According to the first invention, there is provided an electronic device which, in compliance with a predetermined digital interface wherein a predetermined identification code, a processing target discriminating code, a processing field prescribing code and processing information are set, comprises:
means for recognizing the identification code;
means for discriminating the processing target when the identification code is recognized; and
processing means for executing the processing information in accordance with the processing field if the processing target contains its own device. With this arrangement, it is possible to realize the device in which the defective device can be detected and repaired with ease.
According to the second invention, in the electronic device according to the first invention,
a code for targeting all devices and a code for targeting a device of each of the venders are set to the processing target discriminating code, and
the processing information is executed if it is determined that the code for processing all devices or the code for targeting each vender device targets its own device. With this arrangement, processing necessary for the target device can be executed satisfactorily.
According to the third invention, in the electronic device according to the second invention, a processing field prescribing code following the code for targeting all devices and the processing information are determined general-purposely and processing is executed in accordance with them. With this arrangement, processing necessary for the device can be executed satisfactorily.
According to the fourth invention, in the electronic device according to the second invention, the processing field prescribing code following the code for targeting each vender device and the processing information are determined unique to each vender and processing is executed in accordance with them. With this arrangement, processing unique to each vender and which is required by the device can be executed satisfactorily.
According to the fifth invention, in the electronic device according to the second invention, when a master device transmits the processing information for inquiring a malfunction of a device together with the code for targeting all devices, a slave device transmits answer information for the inquiry about the malfunction to the master device. With this arrangement, a defective device can be specified easily.
According to the sixth invention, in the electronic device according to the fifth invention, the slave device includes a diagnosing means for diagnosing the malfunction of the device and information of the diagnosing means is transmitted to the master device as answer information for the inquiry about the malfunction. With this arrangement, a defective device can be specified easily.
According to the seventh invention, in the electronic device according to the fifth invention, the master device includes a communication means for communicating with the outside, and, together with the code for targeting each vender device, the processing information on repairing the slave device and which is determined unique to each vender are transmitted through the communication means. With this arrangement, a defective device can be specified and a defective device can be repaired by a method unique to each vender through the communication from the outside.
According to the eighth invention, in the electronic device according to the first invention, in compliance with an AV/C command of an IEEE 1394 interface, the predetermined identification code is set to the interval of the operation code of the AV/C command and the processing target discriminating code is set to a first of the AV/C command, the processing field prescribing code is set to a second operand and the processing information is set to a third operation land. With this arrangement, a device can be realized by a general-purpose interface.
According to the ninth invention, there is provided an electronic device repair method in which, by setting a predetermined identification code, a processing target discriminating code, a processing field prescribing code and processing information to an arbitrary digital interface, when the identification code is recognized, the processing target is discriminated and if the processing target contains its own device, the processing information is executed in accordance with the processing field. With this arrangement, a defective device can be specified and the defective device can be repaired easily through the digital interface.
According to the tenth invention, in the electronic device repair method according to the ninth invention, a code for targeting all devices and a code for targeting each vender device are set to the processing target discriminating code, and the processing information is executed if it is determined that the code for processing all devices or the code for targeting each vender device targets its own device. With this arrangement, processing necessary for the target device can be executed satisfactorily.
According to the eleventh invention, according to the electronic device repair method according to the tenth invention, a processing field prescribing code following the code for targeting all devices and the processing information are determined general-purposely and processing is executed in accordance with them. With this arrangement, processing necessary for the device can be executed satisfactorily.
According to the twelfth invention, in the electronic device repair method according to the tenth invention, the processing field prescribing code following the code for targeting each vender device and the processing information are determined unique to each vender and processing is executed in accordance with them. With this arrangement, processing unique to each vender and, which is required by the device can be executed satisfactorily.
According to the thirteenth invention, in the electronic device repair method according to the tenth invention, when a master device transmits the processing information for inquiring a defect of a device together with the code for targeting all devices, a slave device transmits answer information for the inquiry about the defect to the master device. With this arrangement, a defective device can be specified easily.
According to the fourteenth invention, in the electronic device repair method according to the thirteenth invention, the slave device diagnoses the defect of the device and a diagnosed result for the inquiry about the defect is transmitted to the master device as the answer information. With this arrangement, a defective device can be specified easily.
According to the fifteenth invention, in the electronic device repair method according to the thirteenth invention, the master device communicates with the outside and the processing information for repairing the slave device and which is determined unique to each vender as well as the code for targeting each vender device are transmitted through the communication. With this arrangement, a defective device can be specified and a defective device can be repaired by a method unique to each vender through the communication from the outside.
According to the sixteenth invention, in the electronic device repair method according to the ninth invention, in compliance with an AV/C command of an IEEE 1394 interface, the predetermined identification code is set to the interval of the operation code of the AV/C command and the processing target discriminating code is set to a first operand of the AV/C command, the processing field prescribing code is set to a second operation land and the processing information is set to a third operand. With this arrangement, a device can be realized by a general-purpose interface.